Bulkhead door, sluice gate, and the like



Nov. 14, 1933. A. L. ASH ET AL 1,935,005

BULKHEAD DOOR, SLUICE GATE, AND THE LIKE Filed May 17 1932 3 Sheets-Sheet 1 s 22 f m 16 0 9 4 5854 J0 t? flyj 19 2.1519 5.148 49 5a NOV-l4, A ASH ET A BULKHEAD DOOR, SLUICE GATE, AND THE LIKE Filed May 17, 1952 3 Sheets-Sheet 2 J 56 a g 1 J3 s Q19 20* I Ea g? i f S g NOV. 14, A L ASH ET AL BULKHEAD DOOR, SLUICE GATE, AND THE LIKE Patented Nov, 14, 1933 UNITED STATES PATENT OFFICE BULKHEAD DOOR, SLUICE GATE, AND THE LIKE AubreyLawrence Ash, Thorpe Bay, and William Pritchard Watkins, London, England, assignors to J; Stone & Company, Limited, Deptford, England, a company of Great Britain Application May17, 1932, Serial No. 611,918, and

' 1 in Great BritainrJune 8, 1931 4 Qlaims. (Cl. 172-239) trie, mqtorthrough a clutch device which is en aged autpmatically upon the attainment of a b ed te j nedmd o peed "Aeoording'to theprincipal feature of the preslQ, ent invention, thelelectric motor is provided with an armature o 'r rotor whichis adapted for being moved axiallywith variation of its speed of rotation either by themagn'eticaction between it and itsfield-systern,or 'stator, or by the action of separatelspeed sensitive means such as a centrifugal gevernor gear, or by a combination of these two aetions, 'Thellast named alternative is preferred. 'This axialm'ove'rnent is useful for two efiects: It maybe utilized firstly to initiate, ef- 2o feet or assist. engagement of the clutch device for connecting themotor tothe door,gate or the like, andsecondly to produce a change in the strength of; field: in which the armature 'is rotating. Thusthefieldl conditions at starting,

2, with thearmature outof register with the field V system,rmay be suchas to en'sure rapid accelerfl ation or-ms motor, whilst those at working speed, with thearmature in its normal position, may be such as to provide the maximum power output. 3 One embodiment of'the "invention as applied to a bulkheaddoor is illustrated by way of example in the accompanying drawings, in which;-

Figure 1 1s a pictorial circuit diagram,

FiguresZ and 3 area vertical section and end view of an electric motor, and

' Figures' i, 5 and 6 avertical section (on the line IVIV"of Figure 6), a plan viewand a part front elevation of an automatic switch.

' Referring 'first'of all'to Figure 1, the installation illustrated comprises inessentials a bulkhead door (1 with an operating rack b meshing witha pinion e' on' a shaft d: Said shaft (1 is adapted for being driven, in a manner hereinafter described; by a motor e through a gear-box f, a shaft g, clutch h and a motor shaft 7'. As illustrated, the electric motor e is a direct current maehme with two poles ,1. Said machine preferably possesses substantially series characteristics'the series windings 2 being designed to give an exceptional fieldstrength so as to obtain the: necessary lifting power at an upper speed limit; For the largest bulkhead doors it has been estimated that a motor developing, say, only L2 at'1,000 -2,0'00 R. P; M, should provide ample power. The motor may be of crane rating as its operation is extremely infrequent and of short duration. As will be appreciated, however, it is desirable that the starting torque should be the maximum possible. Subsidiary shunt field wind- .ings 4 are provided for influencing the running of the motor as will be explained later. "The armature 3 of particularly robust construction is totally enclosed in a cast steel yoke and housing 5 (Figures 2 and 3) and is mounted in bearings 6 provided in the end covers 7; These bearings are advantageously splined sleeve and ball bearings and adapted to permit" of axial movement of said armature. With a'motor e of the rating mentioned above, an axial movement of about out of the normal field position may be provided for. vA loading spring 8 tendingto hold the armature 3 in a lowermost position out of register with the poles is interposed'between the armature 3 and the upper end cover 7. The commutator 9 is suitably extendedto maintain contact, during axial movement ofthe armature 3, with normal brushes l0 and with subsidiary short-cir'cuiting brushes 11 set at 90 electrical degrees to said normal brushes. I

Any appropriate type of robust clutch h, such as a dog clutch, able to withstand a heavy im pact may be employed, but it is desirable that the clutch should be capable of working in either a horizontal or vertical position. Preferably a centrifugal governor device l2ris provided, as illustrated, for engaging, or for assisting the axial movement of the armature 3 in engaging, the clutch device h. It is desirable that this governor 12 should have a substantial-flywheel effect; for example with a motor rating such as has been indicated the governor may be designed to accumu; late'en'ergy up' to, say, 350 inch. lbs. at 2,000 R. P. M. The swinging balls or other elements of the governor are connected to and rotatewith' the armature shaft 7' on one side of the clutch h and are connected to a collar 15 free to rotateon, but'axially immovable in relation to, the shaft g onthe other side of said clutch.

The motor controllershown' in Figures 4-6 has a rockable contact body with three positions, a closing position, an intermediate 01f position and an opening positionp The controller is operated by the cores 18, 19 of a pair of independent solenoids 20, 21 each effective for moving the rockable contact body to the position required by the energization of that solenoid. The gravity-returned cores engage the rockable contact body by way of rod extensions 18 19 and asee-saw bar 22 fast on the spindle 23 of said body, the arrangement being such that when one core is raised by the energization of its solenoid, the other is depressed against a loading spring 24 by the bar 22. When neither solenoid is energized, the loading springs 24 ensure the contact body being definitely held in the off position. The solenoids 20, 21 are selectively energized by a manual remote control switch 25 (Figure l) or by any one of a number of such switches, having three main positions, in an effective off position, and closing and opening positions in which the corresponding solenoids are energized. The remote control switches may be of the lever pattern, giving a clear indication by their position what operation, if any, is in progress. These control switches 25, which, if preferred, may operate in relay circuits, are arranged to control one door a, or a group of such doors. In any case they must be designed for dealing with comparatively highly inductive circuits. The solenoid circuits, or relay circuits, also contain so-called limit switches 26, 27 associated with the door a and adapted for automatically breaking the circuit of the energized solenoid 20, 21 and allowing return of the rockable controller contacts to the off position at or towards the end of an operation. In the case of the vertically movable door a, limit switches of simple construction may be fitted to the door frame and each arranged to make definite contact when not held open by the door. Contact should be broken before the door in closing makes material contact with the bottom sill.

A suitable contact arrangement for the controller is illustrated in Figures 1 and 5. With the rockable contact body in the closing position, i. e. withthe solenoid 21 energized and said body rocked anti-clockwise (Figures 1 and 4), a circult is completed from one main terminal 28 series field thus produced. With the contact body rocked in the clockwise direction to the "opening" position a circuit is completed between the main terminals 28, 43 as follows: fixed contact 29, rockable contact 44, fixed contact 31, part of the series field windings 2, fixed contact 32, rockable contact 45, fixed contact 36, armature 3, fixed contact 35, rockable contact 46, fixed contact 39, part of the series field windings 2, fixed contact 40, rockable contact 47 and fixed contact 42. The direction of the current through the series field windings 2 is the same as it was in the previous instance, but that through the armature 3 is reversed, so that the direction of rotation of the motor is reversed. With the rockable contact body in the off position, the subsidiary brushes 11 are short circuited by way of fixed contacts 48, 49 and rockable contact 50. The fixed contacts are carried by springs 51 which are supported by an insulating bar 52 from brackets 53 in the controller casing 54; The rockable contacts are carried by arms 55 extending from prismatic bodies 56which are clamped, over insulation 57, along the spindle 23 (Figures 4 and 6).

The mode of operation of the embodiment described is as follows Let it be assumed that the door a is open and that a control switch 25 at a remote point, for example the bridge of the vessel, is moved over to the closing position. The limit switch 2'? at or near the bottom sill of the door being closed, the circuit of the closing solenoid 21 is completed and the rockable contact body of the controller is moved to the closing position and acts as a starting switch for the motor e by establishing the connections described above. Since the motor-armature 3 is out of register with the field poles 1, it commences to rotate, in the direction for closing the door a, in a considerably weakened field with the result that acceleration is rapid. When the speed has reached, say, approximately 2,000 R. P. M., the armature 3 will have moved, assisted by the governor 12, into the normal position relatively to the field poles 1 and the clutch It will engage. By this moment considerable power will have been stored in the governor 12 and associated rotating parts, so that on the engagement of the clutch h, an impact of substantial force is transmitted to the pinion and rack mechanism b, c of the door a. Should the first impact be insufficient to start the door moving or should an obstacle be encountered, the motor speed will fall off until the clutch h disengages (at a lower speed than it engaged) and allows the motor to re-accelerate for delivering a further impact, the operation being repeated until the succession of impacts dislodges the door. The door a will then close under the action of the governor 12, assisted by the motor e and gravity, the motor being prevented from running away by its subsidiary shunt field. When the door, approaching the bottom sill, opens the lower limit switch 27, the circuit of the closing solenoid 21 is broken and the rockable contact body of the controller is returned by the spring 24 on the core extension 18 to the off position where it short circuits the subsidiary motor brushes 11. The serious hammer stroke which might be caused at the end of the door movement by the momentum of the rotating parts is cushioned by the effect of this short circuit, since the motor acts momentarily as a generator excited by the shunt windings 4, the series windings 2 being unexcited.

Movement of the control switch 25 to the opening; position results in the door a being opened y a similar process, except that the armature 3 is reversed in its rotation. Owing to the taper grooves in which bulkhead doors are customarily arranged to run in order to ensure water-tightness, the properties of apparatus according to the invention are particularly adapted for the opening of a closed door, successive impacts being delivered to the door until the wedging effect in the taper grooves is overcome.

We claim:

1. Apparatus for operating closures such as bulkhead-doors, sluice gates and the like, comprising an electric motor whereof the rotor is movable axially into the stator with variation of its speed, a non-slip clutch device arranged be tween said rotor and said closure, means for automatically engaging said clutch abruptly upon the attainment, of a predetermined rotor speed, and a connection between said means and said rotor, whereby axial movement of the latter is utilized to initiate engagement of the clutch.

2. Apparatus for operating closures such as bulkhead-doors, sluice gates and the like, comprising an electric motor with a strong series field and an armature axially movable with variation of its speed, a non-slip clutch device between the armature and the closure, means for automatically causing said clutch device to be engaged abruptly upon the attainment of a predetermined armature speed, and a connection between said means and said armature, whereby axial movement of the latter is utilized to initiate engagement of the clutch.

3. Apparatus according to claim 2, wherein the motor has a subsidiary shunt field and subsidiary armature brushes, and automatic means is provided for short circuiting said brushes towards 

